Perl is a platform-independent
programming language, ideally suited for processing text files, such as SGF. I have started a new page for collecting SGF Organising Utilities written in Perl and other platform-independent languages.
Perl can be obtained for Windows-based PCs from Active State, and is also distributed with
Cygwin.
Perl is usually installed on most UNIX/Linux distributions.
Perl is pre-installed on Mac OS X installations.